Method of and apparatus for coating cores



Dec. 16,I 1930. c. MARTELL ET AL METHOD OF' AND APPARATUS FOR COATING CORES Filed Aug. 20, 1927 u N m |14 .wllllln rgi/rivm Patented Dec. 16', 1930 UNITED STATES PATENT oFFlcE CHARLES MARTELL, OF CICERO, AND BERGER AMANDUS HAGEN, OFCHICAGO, ILLI- NOIS, ASSIGNORS T WESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEW YORK,

-N. Y., A CORPORATION OF NEW YORK METHOD' OF AND APPARATUS FOR COATING CORES Application led August 20, 1927. Serial No. 214,224.

'lhis'invention relates to methods of and y apparatus for coating cores, and more partlcularly to methods of and apparatus for applying material'to a continuously loaded submarine cable conductor.

It has been found that the extremely high water pressures to which continuously loaded submarine cables are subjected uponsubmergence tend to deform the loading mate- 10 rial which deformation would'cause the permeability of the loading material to be reduced due to mechanical strains therein. These strains may be introduced as a result of non-uniform pressure experienced by the loading t-ape and to equalize the distribution of such pressure it has been proposed to apply a semi-Huid material between the conductor core and the loading material as well as between the loading material and the 'conductor insulation. A semi-fluid material suitable for this purpose may be a liquid bitumen of thetype specifically referred to in the application of A. R. Kemp, filed January 7, 1923, Serial No. 617,511, and issued February 5, 1929, as Patent No. 1,700,766, which will remain fluid at temperatures and pressures to which the cable is subjected while in service. In order to overcome the tendency of the loading material to become deformed` the semi-fluid material should completely till all of the interstices between the adjacent turns of the loading material or tape andalso the spaces between the tape and the conductor and thereby provide a pressure equahzmg medium for the loading tape wound on `the conductor. n

The primary object of this invention 1s to provide a simple and improved method of and eiliciently operable apparatus for continuously applying material to a core.

In accordance with the general features of the invention an apparatus representative of one means by which the improved method maybe effectively practiced is provided,

` which consists of a vacuum chamber through 'which a loaded conductor may be passed for the purpose of evacuating the interstices between the loading material and the conductor. From this chamber the conductor is passed directly into a second chamber wherein it is further subjected to evacuation and from this chamber the conductor, the interprevent the semi-fluid material from flowing into the evacuating chamber associated therei' with.

These and other objects will be apparent u fromthe following detailed description when considered in connection with the aecompanying drawing, wherein Fig. 1 is a fragmentary plan view of an apparatus representing one embodiment of the invention wherebyV the improved method of continuously., applying filling material may be effectively practiced, the evacuating and Y material filling pipes being broken away to disclose parts otherwise hidden;

Fig. 2 is a central vertical sectional view taken on the line 2 2 of Fig. 1

Fig. 3 is a fragmentary detailed view showing a preferred form of a loaded conductor,

' and .Fig 4 is an enlarged transverse sectional view of the loaded conductor with the semi- Lli'uid i'aterial v'applied"thereto taken ofi" the line 4--4 of Fig. 3.

Referring now to the drawings wherein like numerals have been employed to designate similar parts throughout the various figures, it will be observed that Figs. 1 and 2 disclose a vacuum chamber 10 within a cylindrical casing 11, the chamber 10 communicating with an exhausting mechanism (not shown) through an evacuating pipe 12. The Y secure the disks 18 within the chamber. From the foregoing it will be apparent that when the conductor 14 which may comprise a stranded conductor core 22 surrounded by spiraled loading material or tape 23 is introduced within the evacuating chamber 10, the spaces or interstices between the turns of the spiraled loading tape 23 as well as between the loading tape and the core 22 will be evacuated. After the conductor 14 has been subjected to rarefed conditions within thel chamber l0, it is passed through a tube 24 formed integral with the casing l1 and into a second evacuating chamber 26. y

This evacuating chamber 26 is formed within a housing 27 which is provided with a cover plate 28 and serves as a means in addition to the chamber 10 for exhausting all of the conductor interstices. A vertical Vpartition 29 located medially and extending transversely of the housing 27 separates the vacuum chamber 26 from a liquid retaining chamber 30. The chambers 26 and 30 communicate with an exhausting mechanism (not shown) through the medium of evacuating pipes 31 and 32, res ectively, and a funnel device 34 is provided or supplying the chamber 30 with semi-fluid pressure equalizing material 35. The flow of fluid material 35 from the hopper funnel 34 may be controlled by employing a valve 36 which is interposed between the funnel and the chamber 30. To readily observe the position of the Huid level within the chamber 30a transparent glass plate 38 is employed which is removably secured to the cover plate 28 by means of an annular clamping member 39.* Theclamping member 39 and itsV associatedglass 38 may be readily removed so as to expose the chamber 30 to the atmosphere. When the loaded conductor 14 passes from the chamber 26 into the fluid 35 within the chamber 30, said fluid will readily flow into the exhausted spaces or interstices between the individual'turns 23 and the spaces between the conductor core 22 and the turns 23 as clearly shown in Fig. 4. Thus it willv be apparent that semi-fluid material 35 surrounding theconductor core 22 will serve as a pressure equalizing means for the spiral loading materialor tape and as the conductor passes from the chamber 30 Ainto a restricted conduit 40 a coating of material 35 `will be applied externally of the turns of the loading material 23.

From this restricted conduit 40 the conductor 14 which is now suppliedwith the semifluid material 35 which completely iills all of the spaces between the conductor parts is carried into association with an extruding mechanism -denoted generally by the numeral 42. This extruding mechanism 42 is similar in design to the mechanism disclosed inthe application of Charles Martell and Berger Amandus Hagen, Serial No. 197,469, filed June 8, 1927. A supply of insulating material 43 such as gutta percha is continuously supplied to the extruding mechanism 42 and as the conductor 14 and its applied coating of semi-fluid material passes through a series of nozzles or dies provided in the extruding mechanism 42, a coating of insulating material is uniformly applied to the conductor.

From the foregoing it will be clear that by the practice of this improved method a semi-fluid impregnating or filling material such as a liquid bitumen may be continuously applied to a continuously loaded conductor or cable so as to positively fill all of the spaces or interstices between the conductor or cable parts and to form a coating of semi-fluid material of desired thickness on the outside of the loading tape which will serve as a reservoir of such material throughout the length of the cable. Filling the interstices with the ysemi-fluid material as described causes the material to serve as a means for separati-ng vthe loading tape and the conductor and thereby equalizes or uniformly distributes pressures which are incident to the use of submarine cables under deep-sea conditions. It

will be observed that this lmethod may be practiced without the use of fluid pumps for the purpose of forcing such fluid into the interstices around the conductor core and enables the application of semi-Huid, impregnating material by passing a loaded conductor through a supply of such material which is free from pressures ,in excess of atmospheric pressures. In fact the method may be practiced wherein the supply of semi-fluid material is under the pressures which are less than atmosphericpressures and this is accomplished by evacuating the air above the supply of fluid material. By evacuating the air, above the fluid material any air bubbles ventrapped within the fluid will be removed and by havingthe pressure within the chambers 26 and 30fsubstantially equal, the fluid material 35 will not flow into the chamber 26 between the surface of the conductor 14 and the surface of the aperture within the partition 29 through which the conductor passes. A valve 45 provided in the evacuating pipe 32 serves to disconnect the chamber 30 from the evacuating source when desired.

Although the invention has been described 1n connection with the-application of semifluid material to aA conductor having a covering of spiral loading material lor'tape, it is to be understood that the invention is capable of many other applications and therefore should be limited only by the scope of the appended claims.

. What is claimed is:

1. The method of continuously applying semi-fluid material to a conductor, which consists in passing the conductor continuously through an evacuated area,vthen continuously passing the conductor through a second evacuated area, and through a semi-Huid material adjacent to the second evacuated area, and reducing the pressure upon the semifluid material to prevent said material from ilowinginto the second evacuated area.

2. The method of continuously applying semi-fluid material to a conductor, which consists in passing the conductor continuously through an evacuated area and through a semi-fluid material adjacent to the evacuated area, and reducing the pressure upon the semi-fluid material to prevent the material from flowing into the evacuated area.

3. In an apparatus for'continuously applying material to a core having interstices to be filled, means for continuously receiving and evacuating the interstices of the core, a second evacuating means connected with the rstmentioned means for receivin a core therefrom, a container communicating with the second evacuating means for receiving the evacuated core and for retaining impregnating material, andmeans for maintaining the material under a pressure less than atmospheric pressure to prevent the material from flowing into the second evaclating means.

4. The methodof continuously applying semi-fluid material to a conductor core surrounded by turns of a loading material, which consists in continuously passing the loaded core through an evacuated area to evacuate the spaces between the core and the turns, continuously passing the loaded core through a second and independent evacuated area to further evacuate the spaces between the core and the turns, continuously passing CHARLES MARTELL. BERGER AMANDUS HAGEN.

the loaded conductor through a semi-fluid f material adjacent to the second evacuated area, and reducing the pressure upon the semi-fluid material to prevent the material from flowing into the second evacuated area.

5. In an apparatus for continuously applying' material to a core having interstices to be filled, a plurality of independent evacuating chambers for evacuating the interstices in the core, means for connecting the chambers to. permit the passage of the core from one chamber to another without exposure to the` air, and a container for .receiving the evacuated core and for retaining filling material, and means for evacuating the container to reduce the pressure upon the material below atmospheric pressure.

6. In an apparatus for continuously impregnating a conductor having a covering of ,loading material, a sealed evacuati-ng chamber for receiving a loaded conductor and for evacuating the interstices between the conductor and the loading material, a second sealed evacuating chamber for receiving the conductor from the first mentioned chamber V I and' for further evacnatingV the loaded conductor, amaterial containing chamber communicating with the second evacuating 

